Control of blue mold ( Peronospora tabacina ) was evaluated in field experiments on flue-cured tobacco in 1995 and on Burley tobacco in 1995 and 1996. Plots in each experiment were arranged in a randomized complete block design with four replications. Foliar fungicide treatments were applied with a CO₂-powered back-pack sprayer. Preventive treatments included five sprays that were initiated as soon as the presence of blue mold spores was considered likely and were applied on a 7-day interval. Spray volumes increased from 468 L/ha when plants were knee-high to 935 L/ha when plants were near topping. Curative treatments were initiated only after disease was observed within the experiment. Percent leaf area damaged (% LAD) was estimated for the bottom, middle, and top third of four plants in the center row(s) of each plot. In 1995, curative use of 80 g a.i./ha of Actigard or a tankmix of 40 g a.i./ha of Actigard and 224 g a.i./ha of Ridomil were associated with a lower percentage of flue-cured tobacco leaves with blue mold or target spot lesions than similar use of Ridomil or Dithane alone. Preventive application of DPX-KQ667 improved blue mold control on Burley tobacco in 1995 compared to that achieved with Manzate, Ridomil, Curzate M8, or DPX-KP481, but did not protect the crop from significant damage. In 1996, preventive use of Acrobat MZ or Actigard provided better blue mold control than curative use of the same products or application of Dithane or Aliette. Less intense sporulation was also observed in most Actigard treatments and where Acrobat MZ had been applied preventively. However, treatment effects did not result in significant differences in agronomic traits or percent total alkaloids in leaf tissue. No symptoms of phytotoxicity were observed in any of the experiments.